Identification and characterization of the BAHD acyltransferase malonyl CoA:: Anthocyanidin 5-O-glucoside-6"-O-malonyltransferase (At5MAT) in Arabidopsis thaliana
Identification and characterization of the BAHD acyltransferase malonyl CoA:: Anthocyanidin 5-O-glucoside-6"-O-malonyltransferase (At5MAT) in Arabidopsis thaliana
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DOI：
10.1016/j.febslet.2007.01.060
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发表时间：
2007-03-06
期刊：
影响因子：
3.5
通讯作者：
Gershenzon, Jonathan
中科院分区：
文献类型：
--
作者：
D'Auria, John C.;Reichelt, Michael;Gershenzon, Jonathan
拟南芥中的主要花青素是一种花青素衍生物，经过糖基化以及添加三个酰基部分进行修饰：丙二酰基、对香豆酰基和芥子酰基。我们分离出了 BARD 酰基转移酶家族的一个成员，它通过将反向遗传学方法与生化基因组学相结合来催化这种丙二酰化反应。 At3g29590（编码丙二酰化酶的基因）中含有 T-DNA 插入的突变系不能产生丙二酰化花青素。含有 At3g29590 RNAi 沉默盒的转基因植物证明 At3g29590 基因转录物的减少与丙二酰化花青素的减少之间呈正相关。在一些植物品系中，At3g29590 和编码 5-O-花青素葡萄糖基转移酶的上位基因 At4g14090 的转录水平随着花青素色素的积累而增加。对异源表达和纯化的丙二酰化酶的研究表明，该活性对丙二酰辅酶A和具有5-O-葡萄糖基化的花青素具有特异性。丙二酰基转移本身仅发生在 5-O-葡萄糖苷功能上，而不发生在拟南芥花青素中存在的任何其他糖部分上。因此，体内和体外结果均将 At3g29590 编码酶的活性定义为花青素 5-0-葡萄糖苷-6"-O-丙二酰转移酶 (At5MAT)。(c) 2007 年欧洲生化协会联合会。由 Elsevier B.V 出版。保留所有权利。
The major anthocyanin in A. thaliana is a cyanidin derivative modified by glycosylation as well as by the addition of three acyl moieties: malonyl, p-coumaroyl, and sinapoyl. We have isolated a member of the BARD acyltransferase family which catalyzes this malonylation reaction by combining a reverse genetics approach with biochemical genomics. A mutant line containing a T-DNA insertion in At3g29590, the gene encoding the malonylating enzyme, is incapable of producing malonylated anthocyanins. Transgenic plants harboring an RNAi silencing cassette for At3g29590 demonstrate a positive correlation between reduction in the At3g29590 gene transcript and the decrease of malonylated anthocyanins. Transcript levels for both At3g29590 and the epistatic gene At4g14090, encoding 5-O-anthocyanin glucosyltransferase, increase in several plant lines as they accumulate anthocyanin pigments. Investigation of the heterologously expressed and purified malonylating enzyme showed that the activity is specific for malonyl-CoA and for anthocyanins with 5-O-glucosylation. The malonyl transfer itself occurs only to the 5-O-glucoside function, and not to any of the other sugar moieties present in A. thaliana anthocyanins. Hence, both in vivo and in vitro results define the activity of the At3g29590-encoded enzyme as an anthocyanin 5-0-glucoside-6"-O-malonyltransferase (At5MAT). (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.